Can't solve Segmentation fault (core dumped) in c - c

Question

we are writing a program that has to mimic the Linux shell.
It is consisted of some parts. Every part does what the previous part did, plus something extra.
Part one runs single commands like ls, pwd etc. No parameters no
redirection.
Part two runs single commands plus redirection.
This is where we are stuck.. We compile myShell 2 without errors. But when we are typing any command we get the segmentation fault.
We're sorry for writing almost all out code here(myShell 1 not included), we just wanted to make sure you have everything you need to tell us where we are wrong.
functions.h
#ifndef FUNCTIONS_H
#define FUNCTIONS_H
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#define max 260
extern int argCounter(char *argLine,char *delim);
extern void myExec(char *argLine,int howMany,char *delim);
extern char **argArray(char* argLine,int howMany,char *args[],char *delim);
void myExecRedir(char **tokens,char* argLine, int howMany);
#endif
functions.c
#include "functions.h"
int argCounter(char *argLine,char *delim)
{
char *temp;
memcpy(temp,argLine,strlen(argLine));
char *pointer = strtok(temp, delim);
int counter = 0;
while (pointer != NULL)
{
counter++;
pointer = strtok(NULL, delim);
}
return counter;
}
void myExec(char *argLine,int howMany,char *delim)
{
char temp[max];
memset(temp,0,max);
char *args[howMany];
argLine[strlen(argLine)-1] = '\0';
//argArray breaks the argLine and returns an array that contains each argument
argArray(argLine,howMany,args,delim);
execvp(args[0],args);
perror("ERROR: wrong command!");
}
char **argArray(char *argLine,int howMany,char *args[],char *delim)
{
args[howMany] = NULL;
char *pointer = strtok(argLine, delim);
int counter = 0;
while (pointer != NULL)
{
args[counter]=pointer;
counter++;
pointer = strtok(NULL, delim);
}
return args;
}
void myExecRedir(char **tokens,char* argLine, int howMany)
{
char *delim3="<";
char *delim4=">";
int howManyIn= argCounter(argLine,delim3);
int howManyOut= argCounter(argLine,delim4);
if(howManyOut= howManyIn)
{
int fdin = open(tokens[1],O_RDWR);
int fdout = open(tokens[2],O_RDWR);
if(dup2(fdin,fdout) >= 0)
{
tokens[1]=NULL;
tokens[2]=NULL;
execvp(tokens[0],tokens);
}
else
{
printf("ERROR in dup2\n");
}
}
else if(howManyIn== 0) //means we only have > redirection
{
int fdout = open(tokens[1],O_RDWR);
if(dup2(2,fdout) >= 0)
{
tokens[2]=NULL;
execvp(tokens[0],tokens);
}
else
{
printf("ERROR in dup2\n");
}
}
else //means we only have redirection
{
int fdin = open(tokens[1],O_RDWR);
if(dup2(fdin,1) >= 0)
{
tokens[2]=NULL;
execvp(tokens[0],tokens);
}
else
{
printf("ERROR in dup2\n");
}
}
}
myShell2.c
#include "functions.h"
int main()
{
printf("myshell2>");
pid_t pid,waitPid;
//WE TRIED WITHOU ALLOCATING MEMORY AS WELL
char *argLine = (char *)malloc(max);
char **args = (char **)malloc(max);
char **args2 =( char **)malloc(max);
char **temp = (char **)malloc(max);
char *delim="><";
char *delim2=" ";
int i,howMany,howMany2,status;
while(fgets(argLine,max,stdin) != NULL)
{
howMany= argCounter(argLine,delim);//howMany redirections
args=argArray(argLine,howMany,args,delim);
if (howMany == 1)//means we are at myShell 1
{
howMany2= argCounter(argLine,delim2);
if(howMany2 ==1)//checking if the command has any parameters (like ls -l)
{
printf("myshell2>");
pid = fork();
if (pid < 0)
{
perror("ERROR: Fork failed.\n");
return -1;
}
else if(pid == 0)
{
myExec(args[0],howMany2,delim2);
perror("ERROR: Child should never arrive here.\n");
}
else
{
waitPid = wait(&status);
if (waitPid == -1)
{
perror("ERROR: Waitpid failed.\n");
return -1;
}
}
}
else
{
printf("ERROR: Wrong number of Arguments!\n");//can't run on myshell 2
return(0);
}
}
//means we have redirection (< or >)
for (i=0; i<howMany; i++)
{
argArray(args[i],2,args2,delim2);//args2 contains the tokens without spaces(delim2)
temp[i] = args2[0];
howMany2 = argCounter(args[i],delim2);
if(howMany2 > 1) // eg. ls -l should not run here
{
printf("ERROR: Wrong number of Arguments!\n");//myShell3 should be running this
return(0);
}
}
printf("myshell2>");
pid = fork();
if (pid < 0)
{
perror("ERROR: Fork failed.\n");
return -1;
}
else if(pid == 0)
{
myExecRedir(temp,argLine,howMany);
perror("ERROR: Child should never arrive here.\n");
}
else
{
waitPid = wait(&status);
if (waitPid == -1)
{
perror("ERROR: Waitpid failed.\n");
return -1;
}
}
}
}
Thank you in advance.

Answer 1

char *temp;
memcpy(temp,argLine,strlen(argLine));
char *pointer = strtok(temp, delim);
...
is wrong, you need to reserve space with malloc:
size_t len = strlen(argline);
char *temp = malloc(len + 1);
if (temp == NULL) return 0;
memcpy(temp, argLine, len);
/* NUL-terminate the string */
temp[len] = '\0';
char *pointer = strtok(temp, delim);
...
free(temp);
or you can use the non-standard function (but available on many implementations) strdup:
char *temp = strdup(argline);
if (temp == NULL) return 0;
char *pointer = strtok(temp, delim);
...
free(temp);
char **args = (char **)malloc(max);
is also wrong, if you need to reserve space for n pointers to char use:
char **args = malloc(sizeof(*args) * n); /* don't cast malloc */
or
char **args = malloc(sizeof(char *) * n);